Reamer



E. C. SCHMELZKOPF REAIIER Filed-Nov. 13. 1922 2 Sheets-Sheet 1 Jan. I1924 l.479,484

Ira/anion Fag/aid Jaime/2h,

Patented Jan. 1, 1924.

UNITED STATES PATENT OFFICE.

EDWARD C. SCHMELZKOPF, OF MADISON, WISCONSIN, ASSIGNOR TO GISHOL'I'MACHINE COMPANY, OF MADISON, WISCONSIN, A CORPORATION OF WISCONSIN.

amen.

Application filed ll'ovember 13, 1928. Serial Io. 800,771.

To all whom it may concern:

Be it known that I, EDWARD C. SGHMELZ- KOPF, a citizen of the UnitedStates, residing at Madison, in the county of Dane and State ofWisconsin, have invented certain new and useful Improvements in Reamers,of which the following is a specification.

This invention relates to improvements in reamers, and has referencemore especially to tools of that type which are employed to finish,smooth and size a hole in various metals. It is well known that in theuse of such tools, after a .reamer has finished a number of holes thesharp cutting edges of the tool begin to wear, and the diameter of thehole in the work is thereby reduced a fraction of a thousandth of aninch. In order to keep the hole in the work to a standard dimension, areamer must be quickly and accurately adjusted to its normal diameter.The main object of the present i'nventionis to provide an im rovedreamer that can be adjusted or re-sizeg more easily and in much lesstime than is required for an similar reamer now known.

Another ob ect of the invention is to provide, in a reamer of this type,a bladeclamping device that will not only allow endwise adjustment ofthe blade to increase or decrease the cutting diameter of the tool butwill also automatically take care of slight variations in the clampinlengths of the blades, and will also ena le slight adjustments of thecutting diameter to be made, without requiring any shifting of the discclamp at the lower end of the reamer relatively to the body of the tool.A still further object of the invention is to provide a reamer of thistype in which the blades will be rigidly held in place in all adjustedpositions, so that they will be practically as solid and immovable asthey would be if made integral with the body.

In order that my invention may be readily understood by machinists andothers skilled in the art of machine tools, I have, in the accompanyingdrawings, illustrated two practical embodiments of the invention whichhave been found to satisfactorily effectuate the stated urposes andobjects thereof; and referring t ereto Fig. 1 is a side elevation, inaxial section through its upper half, of a reamer embed ing myinvention, and in which the bla e slots and blades are formed withparallel sides;

Fig. 2 is an end elevation of the complete tool, viewed from the rightof Fig. 1;

Fig. 3 is a half section on the line 3--3 of Fig. 1.

Fig. 4 is a top plan of one of the blades;

Fig. 5 is an end elevation of the blade shown in Fig. 4 viewed from thelower end of the latter;

Figs. 6, 7 and 8 are views corresponding with Figs. 1, 2, and 3, resectivel showing a reamer wherein the lads s ots and blades are taperedboth longitudinally and transversely;

Fig. 9 is an inner side elevation of the blade clamp disc, which is thesame in both forms of rcamer shown;

Fig. 10 is a top plan of the blade shown in Figs. 6, 7 and 8;

Fig. 11 is a side elevation of the same blade as viewed from the bottomof Fig. 10; and Fig. 12 is an end elevation of the same blade viewedfrom the right of Fig. 11.

In both forms of the invention shown, the reamer comprises essentially abody formed with longitudinal blade slots, blades slidably fitting saidslots and formed with inclined end wall portions to secure an inwardcamming effect under endwise pressure b the clamping and holdingdevices, a bla e adjusting ring threaded on the inner end of the reamerbody and formed with a tapered or beveled inner side engaged with theinclined rear end walls of the blades, and a transversely elastic bladeclamp disc attached to the outer end of the body preferably by screwspassed therethrou h and into tapped holes in the body, and iormed with acircumferential flange having a beveled or tapered inner side engagedwith under-cut cam surfaces on the outer end walls of the blades.

Referring first to the form of the inven- I Ill slots 14 in itscircumference, these slots be ing arallel with the axis. The side wallsof tie slots are parallel throu bout, and their bottom walls 15 areforms on a low outward taper or incline from points near the inner endto the outer end thereof as clearly shown in Fig. 1.

The blades 16, of which one is shown in detail in Figs. 4 and 5, areformed of a uniform width to accurately fit the side walls of the slots14, and each blade has a tapered or inclined bottom wall 17 that lies incontact with the inclined bottom wall 15 of the blade slot. On its outerside each blade has a. cutting edge 18, herein shown as oblique, but, ofcourse, the cutting edge may be oblique, arallel or spiral, as desired,since this detail is immaterial to the present invention. Each blade hasat its inner end a downwardly and rearwardly inclined end wall portion19, and at its outer end an under-cut downwardly and forwardly inclinedend wall portion 20.

The inner end of the reamer body is externally threaded for somedistance, as shown at 21, and mounted thereon is a! blade-adjustingring'22 havin an inner beveled side 23 that fits the inc ined end wallportions 19 of the blades and, when the adusting ringA blades len wisein their slots in an obvious and well-known manner; this adjusting ringbeing quite common in reamers of the ty e. The adjusting ring 22 may beprovided with a scale indicated in Fig. 1 b which the fine adjustmentsof the cutting iameter efi'ected by turning lip the ring may beaccurately determined. ounted on the body behind the adjusting ring 22is an ordinary locking rinig 24 to prevent accidental loosening of the ajusting ring 22.

To the forward end of the reamer body is attached by clamp screws 25 anannular disc clamp designated as an entirety by 26. This clamp is formedwith a short inwardly extending peripheral flange 27 that has a beveledor tapered face 28 fitting the undercut tapered or beveled end portions20 of the blades. The reamer body is formed with tapped holes 29 in itsouter end to receive the screws 25; and the disc clamp 26 is formed withcountersunk holes 30 to receive the tapered heads 31 of the screws.Preferably each screw is formed with a central hexagonal socket 32 inits head for the application of a wrench but the particular formation toaccommodate a screw driver is immaterial. j

The disc clamp 26 is made of highl tempered steel and sufiiciently thinto a 0rd a slight. transverse bending capacity in any direction. In a.reamer having an: blades three of these clamp screws are preferablyemployed, one mid-we between each pair of adjacent blades, as own inFig. 2.

is screwed up, advances the The manner in which the blades are rigidlyheld while working, and the manner in which the cutting diameter may beincreased or decreased, will be readily apparent from the foregoin butmay be briefly outlined as follows. l'iith the disc clamp 26 in place,the adjusting ring 22 is turned up until the blades are rigidly clampedendwise by the oppositely tapered walls 23 and 28 of the adjusting ringand disc clamp respectively, which by a camming action draws each bladedownwardl onto the bottom wall of the blade slot. f this does not ivethe exact desired cutting diameter the atter may be increased by backingoil the disc clam sli htly and correspondingly turning up tie a justingring; the reverse of these adjustments obviously effecting a decrease inthe cutting diameter, the outward and inward radial movements of theblades that occur simultaneously with their longitudinal movementsresulting, of course, from the co-operation of the inclined bottom wallsof the blades with the inclined bottom walls of the slots. If the clamlengths, (by which is meant the distance between the tapared end walls19 and 20) of the several lades are not exactly the same, very smallvariations can be taken care of by further tightening of one or more ofthe disc clamp screws 25, which thereby produces a slight inward bendingof the clamping flange 27 tofit the blade or blades that are slightly,under normal clamping length. Moreover, a very slight increase ofcutting diameter can be effected by the application of increasedpressure at the inner ends of the blades by further turning up theadjusting ring 22 alone, the peripheral portion of the disc clamp 26sprin ing outwardly sufilciently to permit such ne adjustment withoutresetting the clamp screws 25. To eflcct adjustments of any substantialamount, however, the ositions of both the ring 22 and the disc 0 amp 26must be shifted endwise of the reamer body.

The form of the invention illustrated in Figs. 6 to 12 inclusiveembodies identically the same structural characteristics, so far as theblade-clamping devices are concerned, as the form shown in Fi 1 to 5inclusive and alread described. 15: this form of the invention, owever,one side wall 33 of each blade slot, instead of being parallel to the oposite wall, is inclined outwardly relatively to the opposite side wall,as clearly shown in Fig. 8 thereby producing a slot of decreasing widthfrom to to bottom, or of wedge shape. The radia y inclined wall 38 isslightly i clined lon 'tudinally relatively to the opposite side we exceat its lower edge which is parallel with 1'. lower edge of the oppositewall,.so that the slot, except at its bottom is slightl wider at itsrear or inner end than at its orward. or outer end,

this characteristic of the slot appearing in perspective in Fig. 7. Theblades 16', of which one is shown in detail in Figs. to 12, of coursehave side walls corres onding with and adapted to fit the side wal ofthe blade slots; the side wall 34 thereof tapering radially and alsolongitudinallfi, except at its lower edge, so as to be para elthroughout with the correspondingly tapered side wall 33 of the slot.

By reason of the transverse or radial wedge formation of the blades andblade slots, the inward clamping action of the adjusting ring 22 and thedisc clamp 26 draws the blades very tightly into the slots and clampsthem in wor ring position with great rigidity. When the cutting diameteris increased or decreased by outward or inward endwise adjustment oftheblades, the radial adjustment of the latter is efiected by the lonitudinal. taper of the co-operatin side walls 33 and 34 of the bladeslot and blade, rather than by any co-operation between the inclinedbottom walls of the slot and blade which are out of contact. Thisconstruction has the advantage over the construction shown in Figs. 1 to5 inclusive, of clam ing the blades under a wedging fit of the b adesthemselves in their slots, so as to obtain even greater ri idit of theblades relatively to the body t an In the first described stucture. Sofar as the blade clampin means are concerned, however, these are ientical with the construction first described.

I claim- 1. In a reaming tool, the combination with a body formed withlongitudinal blade slots,

of blades fittin said slots and formed with beveled end wa s, each ofsaid slots and its blade havin contacting walls that are inclined lenwise relatively to the axis of the bod whereby endwise adjustments ofthe bla es are accompanied by radial ad- 'ustments thereof, a ringthreaded on said y and formed with a beveled inner side fitting andembracing the rear beveled end walls of. said blades, and a transverselyelastic disc clamp op site and adjustably secured to the forwar end wallof said body and having an inwardly directed eripheral flange formedwith a beveled side ttin and embracing the forward beveled end we ofsaid blades.

2. In an ad'ustable reamer, the combination' of a y formed withlongitudinal blade slots, of wedge-shape both lengthwise and crosswiseand narrowest at their bottoms, the longitudinal edges or the bottoms ofsaid slots bein parallel, blades of corresponding wedge-s ape fittingsaid slots with their bottom walls out of contact with the bottom wallsof the latter and formed with beveled rear end portions and oppositelybeveled undercut forward end gortions, an adjusting ring threaded 0n sai7 body and in thrusting and clamping engagement with the rear beveledend portions of said blades, and a transversely elastic annular discclamp opposite and adjustably attached to the forward end of said bodyand formed with a peripheral flange in thrusting and clam ing engagementwith the undercut forward eveled end ortions of said blades.

E WARD C. SCHMELZKOPF.

